全硫代反义寡聚脱氧核苷酸对胃肠道间质瘤细胞株增殖、凋亡及端粒酶活性的影响

Effects of telomerase RNA-targeting antisense oligonucleotides PS-ASODN on proliferation, apoptosis and telomerase activity of the gastrointestinal stromal tumor cell line GIST867 cultured in vitro

目的观察全硫代反义寡聚脱氧核苷酸（PS—ASODN）对胃肠道间质瘤细胞株GIST867增殖、凋亡及端粒酶活性的影响。方法将1tzmolfL伊马替尼和1．25、2．50、5．00、10．00、20．00／xmol／LPS—ASODN作用于GIST867；采用噻唑蓝（MTF）比色法、酶联免疫吸附试验（ELISA）和流式细胞术检测增殖抑制、端粒酶活性和细胞凋亡，应用逆转录-聚合酶链反应（RT-PCR）检测B淋巴细胞／白血病．2（bcl-2）mRNA表达。结果MTY显示PS-ASODN浓度为5．00μmol／L时，抑制作用明显较对照组强；PS-ASODN对端粒酶活性有明显抑制作用并具时间依赖性；流式细胞检测表明PS-ASODN组的细胞凋亡率为（16．16±1．35）％，显著高于伊马替尼组及对照组；RT—PCR检测表明PS．ASODN可显著下调bcl-2mRNA的表达。结论PS-ASODN可能通过抑制端粒酶活性并下调bcl-2基因表达从而抑制GIST867细胞增殖及诱导细胞凋亡。

Objective -To explore effects of the telomerase RNA-targeting antisense oligonucleoti- des PS-ASODN on proliferation, apoptosis and telomerase activity of the gastrointestinal stromal tumor cell line GIST867 cultured in vitro. Methods GIST867 cells in exponential phase were divided into following groups： control group, 1 ~mol/L imatinib group, and 1.25, 2. 50, 5.00, 10.00 and 20. 00 μmol/L PS- ASODN groups. The anti-proliferation effect on GIST867 cells was determined by methyl thiazol tetrazolimn （MTT） assay. The activity of telomerase was tested by using enzyme linked immunosorbent assay （ELISA）. Apoptosis was examined by using flow cytometry. Reverse transcription-polymerase chain reaction （RT-PCR） was used to detect the expression of B lymphocytes/leukemia-2 （bcl-2） mRNA. Results MTY assay showed PS-ASODN could apparently inhibit the growth of GIST867 cells in a dose-dependent manner. The group of 5.00μmol/L concentration showed more effectiveness than control group. PS- ASODN could apparently inhibit the telomerase activity in a time-dependent manner. Flow cytometry re- vealed that the apoptosis rate of the cells treated by PS-ASODN was （ 16. 16 -＋ 1.35） % , significantly higher than that in the control group and the imatinib group. Treatment with PS-ASODN significantly reduced the bel-2 mRNA expression in the GIST867 cells. Conclusion PS-ASODN can repress the cell prolifera- tion and induce the apoptosis of the GIST867 cells, which may be mediated by inhibition of the telomerase activity and down-regulation of the expression of bcl-2.